1. Field of the Invention
This invention relates to an after-wash treatment preparation based on natural and synthetic layer silicates which is particularly suitable for rinse-cycle softening of textiles.
2. Description of Related Art
After washing and drying, textile fabrics can tend to have a hard, unpleasant feeling on the skin because of the hardness of the water. In order to restore or improve the softness or fluffiness of the fabrics, the articles of laundry may be treated before drying with so-called fabric softeners whih give the fabrics a soft feel by various mechanisms. These fabric softeners are generally cationic compounds a large number of which have been proposed in the field of fabric softeners. Besides fabric softening preparations based on cationic fabric softeners, synergistic combinations of different cationic compounds alone or in admixture with surfactants and other additives (for example fatty acids, soaps, glycerol esters) have been proposed (cf. for example German patent application No. 29 43 606, German patent application No. 23 52 955, European Pat. No. 0 051 983, European patent application No. 0 122 140, European Pat. No. 0 013 780 and European patent application No. 0 107 479). Fabric softeners based on these active components are primarily intended for use in the rinse cycle following the washing process. These active substances may also be used in tumble dryers in the form of sheets coated with active substances (cf. German patent application No. 19 65 470 and European Pat. No. 0 007 135). Another method of fabric care in the laundry field is to use a fabric-softening compound as a constituent of a detergent formulation. Besides cationic active substances and a number of other additives, compounds known generically as layer silicates have been proposed as a softening component in detergent formulations (German patent application Nos. 33 44 098 and 25 26 248). It has been found from extensive investigations, however, that the softening effect of commercial fabric softeners in rinse-cycle softening is not even approached by wash-cycle softening.
Accordingly, an object of the present invention is to provide a highly effective after-wash treatment preparation based on layer silicates for rinse-cycle softening of textiles.
In the course of extensive development work, the poor dispersibility in water and the high pH value of the rinse solution were found to be serious drawbacks with respect to known after-wash treatment preparations where layer silicates are used without additives. After-wash treatment preparations based on layer silicates which have the features of a fabric-care after-treatment preparation must have the following performance characteristics;
good softening power, PA1 high water uptake capacity of the treated fabrics, PA1 good antistatic finishing of the fabrics, PA1 good dispersibility in water, PA1 good dispensability from the dispensing compartments of washing machines, PA1 good product stability, and PA1 good perfumability of the product and the laundry tested therewith. PA1 (a) from 5 to 80% by weight of at least one natural and/or synthetic layer silicate, PA1 (b) from 1 to 20% by weight of a neutralizing agent or souring agent selected from citric acid, maleic acid, oxalic acid, lactic acid, and toluenesulfonic acid, PA1 (c) from 1 to 20% by weight of at least one disintegrating agent comprising citric acid hydrogen carbonate, PA1 (d) from 1 to 30% by weight of at least one filler or carrier substance selected from ammonium sulfate, zeolite A, and urea, PA1 (e) from 0 to 50% by weight of at least one binder, and PA1 (f) from 0 to 10% by weight of a fatty acid ester. PA1 R is a C.sub.10 -C.sub.20 alkyl radical, PA1 n is an integer of from 2 to 10, PA1 R.sup.1 and R.sup.2, which may be the same or different, represent C.sub.2 H.sub.4 OH or an ester thereof with a C.sub.10 -C.sub.20 monocarboxylic acid or sulfosuccinic acid or the alkali metal salt of these acids, and/or